. 2012 Dec 26;59(2):174–179. doi: 10.1262/jrd.2012-148

Table 1. Comparison of mitochondrial DNA copy number of embryos 48 h after insemination among age groups.

Developmental stage	mtDNA number (Mean ± SE)
Developmental stage	All ages (n=49)			Young (n=18)			Middle (n=12)			Aged (n=19)			Aged (>180)* (n=7)
>7-cell	587,536	±	104,277^a	501,818	±	163,051	674,356	±	216,656	647,661	±	203,372	118,408	±	106,535
4-to 7-cell	463,796	±	49,815^ab	563,569	±	52,664	357,376	±	64,052	446,055	±	81,851	301,181	±	52,016
2-to 3-cell	397,852	±	43,731^ab	335,085	±	74,154	336,218	±	87,734	494,735	±	69,936	240,436	±	65,043
Non cleaved	353,039	±	43,345^b	444,072	±	78,958	286,554	±	69,663	332,980	±	63,891	141,590	±	64,694
All	418,020	±	42,183^ab	495,612	±	91,018	342,556	±	40,022	392,173	±	60,445	216,472	±	30,764

Embryos 48 h after insemination were divided into >7-cell stage, 4-to 7-cell stage and 2-to 3-cell stage embryos and noncleaved oocytes. mtDNA number per stage was measured. Cows were divided into age groups: Young 25–45 months, Middle, 45–120 months, Aged, >120 months, and Aged* >180 months. a–b: P<0.05.